Thin film transistor array panel and organic light emitting diode display including the same

ABSTRACT

An exemplary embodiment of the present invention provides a thin film transistor array panel and an organic light emitting diode display including the same including a substrate, a semiconductor disposed on the substrate, a first gate insulation layer disposed on the semiconductor, and a first diffusion barrier layer disposed on the first gate insulation layer. A second diffusion barrier layer is disposed on a lateral surface of the first diffusion barrier layer. A first gate electrode is disposed on the first diffusion barrier layer. A source electrode and a drain electrode are connected to the semiconductor. The first diffusion barrier layer comprises a metal, and the second diffusion barrier layer comprises a metal oxide including the metal.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.15/237,866, filed on Aug. 16, 2016, which claims priority under 35U.S.C. § 119 to Korean Patent Application No. 10-2015-0170781 filed inthe Korean Intellectual Property Office on Dec. 2, 2015, the disclosureof which are incorporated by reference herein in their entirety.

1. TECHNICAL FIELD

Exemplary embodiments of the present invention relate to a thin filmtransistor array panel, and more particularly to an organic lightemitting diode display including the same.

2. DISCUSSION OF RELATED ART

An organic light emitting diode display may include two electrodes andan organic emission layer disposed between the two electrodes. Electronsinjected from one electrode and holes injected from the other electrodemay combine to form excitons in the organic emission layer. When theexcitons are changed from an excited state to a ground state, energy isreleased, thereby emitting light.

An organic light emitting diode display may include a plurality ofpixels each of which may include an organic light emitting diode that isa self-emissive element. A plurality of transistors and at least onecapacitor may be formed in each of the pixels to drive the organic lightemitting diode. The transistors may include a switching transistor and adriving transistor.

The transistors may be top-gate type transistors in which a gateelectrode is disposed on a semiconductor. The semiconductor may includean oxide semiconductor material, and the gate electrode may include arelatively low resistance metal such as copper.

SUMMARY

Exemplary embodiments of the present invention may provide a thin filmtransistor array panel and an organic light emitting diode displayincluding the same.

An exemplary embodiment of the present invention provides a thin filmtransistor array panel including a substrate, a semiconductor disposedon the substrate, a first gate insulation layer disposed on thesemiconductor, and a first diffusion barrier layer disposed on the firstgate insulation layer. A second diffusion barrier layer is disposed on alateral surface of the first diffusion barrier layer. A first gateelectrode is disposed on the first diffusion barrier layer. A sourceelectrode and a drain electrode are connected to the semiconductor. Thefirst diffusion barrier layer includes a metal, and the second diffusionbarrier layer includes a metal oxide including the metal.

Lateral edges of the first diffusion barrier layer and the first gateelectrode may be substantially aligned with each other.

The semiconductor may include an oxide semiconductor material, and thefirst gate electrode may include copper.

The first diffusion barrier layer may include titanium, and the seconddiffusion barrier layer may include titanium oxide.

The semiconductor may include a channel region, and a source region anda drain region disposed on opposite sides of the channel region.

The first gate insulation layer, the first diffusion barrier layer, andthe first gate electrode may overlap the channel region of thesemiconductor. The second diffusion barrier layer may overlap the sourceregion and the drain region of the semiconductor.

The second diffusion barrier layer may contact a lateral surface of thefirst gate insulation layer. The second diffusion barrier layer may bedisposed directly on the source region and the drain region of thesemiconductor.

The first gate insulation layer need not overlap the source region andthe drain region of the semiconductor.

The second diffusion barrier layer may cover upper surfaces and lateralsurfaces of the source region and the drain region of the semiconductor.

The second diffusion barrier layer may be substantially entirelyoverlapped with the source region and the drain region of thesemiconductor.

The first gate insulation layer may be disposed directly on the channelregion, the source region, and the drain region of the semiconductor.The second diffusion barrier layer may be disposed directly on the firstgate insulation layer.

The second diffusion barrier layer may be substantially entirelyoverlapped with the source region and the drain region of thesemiconductor.

A second gate insulation layer disposed on the first gate electrode, thesecond diffusion barrier layer, and the semiconductor may further beincluded. The second gate insulation layer may be disposed directly onthe source region and the drain region of the semiconductor.

The second diffusion barrier layer may be partially overlapped with thesource region and the drain region of the semiconductor.

An exemplary embodiment of the present invention may provide a thin filmtransistor array panel that may include a second gate insulation layerdisposed on the first gate electrode and the second diffusion barrierlayer, a second gate electrode disposed on the second gate insulationlayer, and an interlayer insulation layer disposed on the second gateelectrode and the second gate insulation layer. The source electrode andthe drain electrode may be disposed on the interlayer insulation layer.

The second gate insulation layer may include silicon nitride.

An exemplary embodiment of the present invention provides an organiclight emitting diode display including a substrate, a semiconductordisposed on the substrate, a first gate insulation layer disposed on thesemiconductor, and a first diffusion barrier layer disposed on the firstgate insulation layer. A second diffusion barrier layer is disposed on alateral surface of the first diffusion barrier layer. A first gateelectrode is disposed on the first diffusion barrier layer. A sourceelectrode and a drain electrode are connected to the semiconductor. Afirst electrode is connected to the drain electrode. An organic emissionlayer is disposed on the first electrode, and a second electrode isdisposed on the organic emission layer. The first diffusion barrierlayer includes a metal, and the second diffusion barrier layer includesa metal oxide including the metal.

Lateral edges of the first diffusion barrier layer and the first gateelectrode may be substantially aligned with each other.

The semiconductor may include an oxide semiconductor material. The firstgate electrode may include copper. The first diffusion barrier layer mayinclude titanium. The second diffusion barrier layer may includetitanium oxide.

The semiconductor may include a channel region and a source region and adrain region disposed on opposite sides of the channel region. The firstgate insulation layer, the first diffusion barrier layer, and the firstgate electrode may overlap the channel region of the semiconductor. Thesecond diffusion barrier layer may overlap the source region and thedrain region of the semiconductor.

In the thin film transistor array panel and the organic light emittingdiode display including the same according to some exemplary embodimentsof the present invention, the edges of the first diffusion barrier layerand the first gate electrode may be substantially aligned with eachother by forming the second diffusion barrier layer which contacts thelateral surface of the first diffusion barrier layer. Thus, performanceof the thin film transistor may be prevented from deteriorating. Thefirst diffusion barrier layer might not be protruded more than the firstgate electrode, and thus a reduction in performance of the thin filmtransistor according to an exemplary embodiment of the present inventionmay be reduced or prevented.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the inventive concept will become moreapparent by describing in detail exemplary embodiments thereof, withreference to the accompanying, in which:

FIG. 1 is a cross-sectional view illustrating an organic light emittingdiode display according to an exemplary embodiment of the presentinvention.

FIG. 2 to FIG. 6 are process cross-sectional views illustrating amanufacturing method of an organic light emitting diode displayaccording to an exemplary embodiment of the present invention.

FIG. 7 is a cross-sectional view illustrating an organic light emittingdiode display according to an exemplary embodiment of the presentinvention.

FIG. 8 to FIG. 11 are process cross-sectional views illustrating amanufacturing method of an organic light emitting diode displayaccording to an exemplary embodiment of the present invention.

FIG. 12 is a cross-sectional view illustrating an organic light emittingdiode display according to an exemplary embodiment of the presentinvention.

FIG. 13 to FIG. 17 are process cross-sectional views illustrating amanufacturing method of an organic light emitting diode displayaccording to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Exemplary embodiments of the present invention will be described in moredetail below with reference to the accompanying drawings, in whichexemplary embodiments of the present invention are shown. As thoseskilled in the art would realize, the described embodiments may bemodified in various different ways, all without departing from thespirit or scope of the present invention.

In the drawings, the thicknesses of layers, films, panels, or regionsmay be exaggerated for clarity. Like reference numerals may refer tolike elements throughout the specification and drawings. It will beunderstood that when an element such as a layer, film, region, orsubstrate is referred to as being “on” another element, it may bedirectly on the other element or intervening elements may be present.

An organic light emitting diode display according to an exemplaryembodiment of the present invention will be described in more detailbelow with reference to FIG. 1.

FIG. 1 is a cross-sectional view illustrating an organic light emittingdiode display according to an exemplary embodiment of the presentinvention.

Referring to FIG. 1, the organic light emitting diode display accordingto an exemplary embodiment of the present invention may include asubstrate 110, a semiconductor 130 disposed on the substrate 110, afirst gate insulation layer 141 disposed on the semiconductor 130, afirst diffusion barrier layer 151 disposed on the first gate insulationlayer 141, a second diffusion barrier layer 159 in contact with alateral surface of the first diffusion barrier layer 151, and a firstgate electrode 152 disposed on the first diffusion barrier layer 151.

The substrate 110 may include an insulating substrate. The insulatingsubstrate may include glass, quartz, ceramic, or plastic. However,exemplary embodiments of the present invention are not limited thereto,and the substrate 110 may include a metal substrate. The metal substratemay include stainless steel.

A buffer layer 120 may be disposed on the substrate 110. The bufferlayer 120 may include a silicon nitride (SiN_(x)) or a silicon oxide(SiO_(x)). The buffer layer 120 may reduce or prevent impurities ormoisture from infiltrating the substrate 110 (e.g., while planarizing asurface of the substrate 110). According to an exemplary embodiment ofthe present invention, the buffer layer 120 may be omitted.

The semiconductor 130 may be disposed on the buffer layer 120. Thesemiconductor 130 may include an oxide semiconductor material. Thesemiconductor 130 may include a channel region 131 to which an impurityis not doped, and contact doping regions 132 and 133 disposed onopposite sides of the channel region 131 and to which an impurity isdoped. The contact doping regions 132 and 133 may include a sourceregion 132 and a drain region 133. The impurity may be selecteddepending on a type of a thin film transistor.

The first gate insulation layer 141 may include silicon nitride(SiN_(x)) or silicon oxide (SiO_(x)). The first gate insulation layer141 may overlap the channel region 131 of the semiconductor 130. Thefirst gate insulation layer 141 need not overlap the source region 132and the drain region 133 of the semiconductor 130.

The first diffusion barrier layer 151 may include a metal. For example,the first diffusion barrier layer 151 may include titanium (Ti). Thefirst diffusion barrier layer 151 may overlap the channel region 131 ofthe semiconductor 130. The first diffusion barrier layer 151 need notoverlap the source region 132 and the drain region 133 of thesemiconductor 130.

The second diffusion barrier layer 159 may include a metal oxideincluding the same metal as the first diffusion barrier layer 151. Forexample, the second diffusion barrier layer 159 may include titaniumoxide (TiO_(x)). The second diffusion barrier layer 159 may overlap thesource region 132 and the drain region 133 of the semiconductor 130. Thesecond diffusion barrier layer 159 may be disposed directly on thesource region 132 and the drain region 133 of the semiconductor 130. Thesecond diffusion barrier layer 159 may cover upper surfaces and lateralsurfaces of the source region 132 and the drain region 133 of thesemiconductor 130. The second diffusion barrier layer 159 may besubstantially entirely overlapped with the source region 132 and thedrain region 133 of the semiconductor 130. The second diffusion barrierlayer 159 may contact a lateral surface of the first gate insulationlayer 141 and may be disposed on the buffer layer 120.

The first gate electrode 152 may include copper (Cu). The first gateelectrode 152 may overlap the channel region 131 of the semiconductor130. Planar shapes of the first gate electrode 152 and the firstdiffusion barrier layer 151 may be substantially identical to eachother. The first gate electrode 152 and the first diffusion barrierlayer 151 may have a substantially identical planar shape at acontacting surface between the first gate electrode 152 and the firstdiffusion barrier layer 151. Lateral surfaces of the first gateelectrode 152 and the first diffusion barrier layer 151 may have atapered shape, and thus, planar shapes of the first gate electrode 152and the first diffusion barrier layer 151 may be substantially identicalto each other. However, according to an exemplary embodiment of thepresent invention planar sizes of the first gate electrode 152 and thefirst diffusion barrier layer 151 may be slightly different from eachother. Thus, lateral edges of the first gate electrode 152 and the firstdiffusion barrier layer 151 may be substantially aligned with eachother.

A second gate insulation layer 142 may be disposed on the first gateelectrode 152 and the second diffusion barrier layer 159. The secondgate insulation layer 142 may include silicon nitride (SiN_(x)).

In an exemplary embodiment of the present invention, the first gateelectrode 152 may include copper (Cu). The second gate insulation layer142 may be formed after the first gate electrode 152 is formed. Sincethe second gate insulation layer 142 may include silicon nitride(SiN_(x)), oxidation of copper may be reduced or prevented during aprocess of forming the second gate insulation layer 142. Since the firstdiffusion barrier layer 151 may be disposed under the first gateelectrode 152, a diffusion of hydrogen into the semiconductor 130 duringthe process of forming the second gate insulation layer 142 may bereduced or prevented. The semiconductor 130 may be an oxidesemiconductor. The second diffusion barrier layer 159 contacting thefirst diffusion barrier layer 151 may include a metal oxide instead of ametallic material, and edges of the first diffusion barrier layer 151and the first gate electrode 152 may substantially coincide with eachother. Thus, a relatively high current may be prevented from flowing atan edge of the first diffusion barrier layer 151. Thus, performance ofthe thin film transistor may be prevented from deteriorating.

A second gate electrode 154 may be disposed on the second gateinsulation layer 142. The second gate electrode 154 may overlap thefirst gate electrode 152.

An interlayer insulation layer 160 may be disposed on the second gateelectrode 154 and the second gate insulation layer 142.

Contact holes 162 and 164 exposing at least a part of the semiconductor130 may be formed in the second diffusion barrier layer 159, the secondgate insulation layer 142, and the interlayer insulation layer 160. Thecontact holes 162 and 164 may expose the contact doping regions 132 and133 of the semiconductor 130.

A source electrode 173 and a drain electrode 175 may be disposed on theinterlayer insulation layer 160. The source electrode 173 may beconnected to the source region 132 of the semiconductor 130 through thecontact hole 162, and the drain electrode 175 may be connected to thedrain region 133 of the semiconductor 130 through the contact hole 164.

Thus, the semiconductor 130, the first gate electrode 152, the sourceelectrode 173, and the drain electrode 175 may be included in one thinfilm transistor. The thin film transistor may be a switching transistoror a driving transistor. The substrate 110 in which the thin filmtransistor is formed may be referred to as a thin film transistor arraypanel.

A passivation layer 180 may be disposed on the interlayer insulationlayer 160, the source electrode 173, and the drain electrode 175. Acontact hole 181 may be formed in the passivation layer 180 to expose atleast a part of the drain electrode.

A pixel electrode 191 may be disposed on the passivation layer 180. Thepixel electrode 191 may include a transparent conductive material suchas indium-tin oxide (ITO), indium-zinc oxide (IZO), zinc oxide (ZnO), orindium oxide (In₂O₃), or a reflective metal such as lithium (Li),calcium (Ca), lithium fluoride/calcium (LiF/Ca), lithiumfluoride/aluminum (LiF/AI), aluminum (Al), silver (Ag), magnesium (Mg),or gold (Au). The pixel electrode 191 may be electrically connected tothe drain electrode 175 through the contact hole 181 to serve as ananode of an organic light emitting diode (OLED).

A pixel definition layer 350 may be disposed on the passivation layer180 and an edge portion of the pixel electrode 191. The pixel definitionlayer 350 may include a pixel opening 351 exposing the pixel electrode191. The pixel definition layer 350 may include a resin such as apolyacrylate, or a polyimide, or a silica-based inorganic material.

An organic emission layer 370 may be formed in the pixel opening 351 ofthe pixel definition layer 350. The organic emission layer 370 mayinclude at least one of an emission layer, a hole-injection layer (HIL),a hole-transport layer (HTL), an electron-transport layer (ETL), and anelectron-injection layer (EIL).

The organic emission layer 370 may include a red organic emission layeremitting red light, a green organic emission layer emitting green light,and a blue organic emission layer emitting blue light. According to anexemplary embodiment of the present invention, the red organic emissionlayer, the green organic emission layer, and the blue organic emissionlayer may be respectively formed in a red pixel, a green pixel, and ablue pixel to display a color image.

According to an exemplary embodiment of the present invention, theorganic emission layer 370 may display a color image by stacking a redorganic emission layer, a green organic emission layer, and a blueorganic emission layer in each of a red pixel, a green pixel, and a bluepixel to form a red filter, a green filter, and a blue filter for eachpixel. According to an exemplary embodiment of the present invention, acolor image may be displayed by forming a white organic emission layeremitting white light in each of the red pixel, the green pixel, and theblue pixel to form a red filter, a green filter, and a blue filter foreach pixel. When a color image is displayed by using the white organicemission layer and the color filters, a deposition mask for depositing ared organic emission layer, a green organic emission layer, and a blueorganic emission layer on each of the pixels (e.g., the red pixel, thegreen pixel, and the blue pixel) may be omitted.

The white organic emission layer may include one organic emission layer,or may include a plurality of organic emission layers to emit whitelight. Alternatively, the white organic emission layer may include atleast one yellow organic emission layer and at least one blue organicemission layer to emit white light, by combining at least one cyanorganic emission layer and at least one red organic emission layer toemit white light, by combining at least one magenta organic emissionlayer and at least one green organic emission layer to emit white light,and the like.

A common electrode 270 may be disposed on the pixel definition layer 350and the organic emission layer 370. The common electrode 270 may includea transparent conductive material such as indium-tin oxide (ITO),indium-zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In₂O₃), or thelike, or a reflective metal such as lithium (Li), calcium (Ca), lithiumfluoride/calcium (LiF/Ca), lithium fluoride/aluminum (LiF/Al), aluminum(Al), silver (Ag), magnesium (Mg), or gold (Au). The common electrode270 may serve as a cathode of an organic light emitting diode (OLED).The pixel electrode 191, the organic emission layer 370, and the commonelectrode 270 may be included in the organic light emitting diode(OLED).

An organic light emitting diode display according to an exemplaryembodiment of the present invention may include a first storageelectrode 153 disposed on the substrate 110 and a second storageelectrode 155 overlapping the first storage electrode 153.

The first diffusion barrier layer 151, the first gate insulation layer141, and the buffer layer 120 may be disposed under the first storageelectrode 153. The second gate insulation layer 142 may be disposedbetween the first storage electrode 153 and the second storage electrode155. The first storage electrode 153 and the second storage electrode155 may be included in a storage capacitor together with the second gateinsulation layer 142 as a dielectric material.

A manufacturing method of an organic light emitting diode displayaccording to an exemplary embodiment of the present invention will bedescribed in more detail below with reference to FIG. 2 to FIG. 6.

FIG. 2 to FIG. 6 are process cross-sectional views illustrating amanufacturing method of an organic light emitting diode displayaccording to an exemplary embodiment of the present invention.

Referring to FIG. 2, the buffer layer 120 may be formed by depositingsilicon nitride (SiN_(x)) or silicon oxide (SiO_(x)) on the substrate110.

The semiconductor 130 may be formed by depositing an oxide semiconductormaterial on the buffer layer 120 and then patterning it.

The first gate insulation layer 141 may be formed by depositing siliconnitride (SiN_(x)) or silicon oxide (SiO_(x)) on the semiconductor 130and the buffer layer 120 and then patterning it.

The semiconductor 130 may include the channel region 131, and the sourceregion 132 and the drain region 133 disposed on opposite sides of thechannel region 131. The first gate insulation layer 141 may overlap thechannel region 131 of the semiconductor 130.

Referring to FIG. 3, a first metallic material layer 510 and a secondmetallic material layer 520 may be sequentially deposited on the firstgate insulation layer 141, the semiconductor 130, and the buffer layer120. The first metallic material layer 510 may include titanium (Ti),and the second metallic material layer 520 may include copper (Cu).

A photoresist pattern 600 may be formed by coating a photosensitivematerial on the second metallic material layer 520 and then patterningit.

Referring to FIG. 4, the first gate electrode 152 and the first storageelectrode 153 may be formed by etching the second metallic materiallayer 520 using the photoresist pattern 600 as a mask.

The second diffusion barrier layer 159 may be formed by oxidizing thefirst metallic material layer 510 using the photoresist pattern 600 as amask. A part of the first metallic material layer 510, which is disposedunder the photoresist pattern 600, and thus might not be oxidized, mayserve as the first diffusion barrier layer 151.

Thus, the first diffusion barrier layer 151 may include titanium (Ti),and the second diffusion barrier layer 159 may include titanium oxide(TiO_(x)).

In an exemplary embodiment of the present invention, the photoresistpattern 600 may be employed as a mask to etch the second metallicmaterial layer 520 and to oxidize the first metallic material layer 510.Thus, planar shapes of the first gate electrode 152 and the firstdiffusion barrier layer 151 may be substantially identical to eachother. Edges of the first gate electrode 152 and the first diffusionbarrier layer 151 may substantially coincide with each other, and thefirst diffusion barrier layer 151 need not protrude more than the firstgate electrode 152. Thus, a relatively high current may be reduced orprevented from being generated at an edge of the first diffusion barrierlayer 151, and performance of the thin film transistor may be preventedfrom deteriorating.

Referring to FIG. 5, the photoresist pattern 600 may be removed.

Referring to FIG. 6, the second gate insulation layer 142 may be formedby depositing silicon nitride (SiN_(x)) on the first gate electrode 152and the second diffusion barrier layer 159.

The second gate electrode 154 overlapping the first gate electrode 152and the second storage electrode 155 formed overlapping the firststorage electrode 153 may be formed by depositing a metal material onthe second gate insulation layer 142 and then patterning it.

The interlayer insulation layer 160 may be disposed on the secondstorage electrode 155 and the second gate insulation layer 142. Thecontact holes 162 and 164 exposing the source region 132 and the drainregion 133 of the semiconductor 130 may be formed by patterning theinterlayer insulation layer 160.

The source electrode 173 and the drain electrode 175 may be formed bydepositing a metal material on the interlayer insulation layer 160 andthen patterning it. The source electrode 173 and the drain electrode 175may be respectively connected to the source region 132 and the drainregion 133 of the semiconductor 130 through the contact holes 162 and164.

The passivation layer 180 may be disposed on the source electrode 173,the drain electrode 175, and the interlayer insulation layer 160. Thecontact hole 181 exposing the drain electrode 175 may be formed bypatterning the passivation layer 180.

The pixel electrode 191 may be formed by depositing a metal material onthe passivation layer 180 and then patterning it. The pixel electrode191 may be connected to the drain electrode 175 through the contact hole181.

The pixel definition layer 350 may be formed by depositing an insulatingmaterial on the pixel electrode 191 and the passivation layer 180 andthen patterning it. The pixel definition layer 350 may include the pixelopening 351 formed to expose the pixel electrode 191.

The organic emission layer 370 may be formed in the pixel opening 351.The common electrode 270 may be formed by depositing a metal material onthe organic emission layer 370 and the pixel definition layer 350 andthen patterning it.

An organic light emitting diode display according to an exemplaryembodiment of the present invention will be described in more detailbelow with reference to FIG. 7.

Since the organic light emitting diode display according to an exemplaryembodiment of the present invention described with reference to FIG. 7may include substantially identical elements to those of the organiclight emitting diode display according to an exemplary embodiment of thepresent invention described with reference to FIG. 1, duplicativedescriptions may be omitted. Referring to FIG. 7, a first gateinsulation layer may cover a source region and a drain region as well asa channel region of a semiconductor. The semiconductor will be describedin more detail below with reference to FIG. 7.

FIG. 7 is a cross-sectional view illustrating the organic light emittingdiode display according to an exemplary embodiment of the presentinvention.

Referring to FIG. 7, the organic light emitting diode display accordingto an exemplary embodiment of the present invention may include thesubstrate 110, the semiconductor 130 disposed on the substrate 110, thefirst gate insulation layer 141 disposed on the semiconductor 130, thefirst diffusion barrier layer 151 disposed on the first gate insulationlayer 141, the second diffusion barrier layer 159 in contact with alateral surface of the first diffusion barrier layer 151, and the firstgate electrode 152 disposed on the first diffusion barrier layer 151.

According to an exemplary embodiment of the present invention, the firstgate insulation layer 141 may overlap the channel region 131 of thesemiconductor 130, and might not overlap the source region 132 and thedrain region 133. However, according to another exemplary embodiment ofthe present invention, the first gate insulation layer 141 may overlapthe channel region 131, the source region 132, and the drain region 133of the semiconductor 130. The first gate insulation layer 141 may bedisposed directly on the channel region 131, the source region 132, andthe drain region 133 of the semiconductor 130. The first gate insulationlayer 141 may cover both of an upper surface and a lateral surface ofthe semiconductor 130.

According to an exemplary embodiment of the present invention, thesecond diffusion barrier layer 159 may be disposed directly on thesource region 132 and the drain region 133 of the semiconductor 130.However, according to another exemplary embodiment of the presentinvention, the first gate insulation layer 141 may be disposed betweenthe second diffusion barrier layer 159 and the source region 132 of thesemiconductor 130 and between the second diffusion barrier layer 159 andthe drain region 133 of the semiconductor 130. Thus, the seconddiffusion barrier layer 159 may be disposed directly on the first gateinsulation layer 141.

A manufacturing method of an organic light emitting diode displayaccording to an exemplary embodiment of the present invention will bedescribed in more detail below with reference to FIG. 8 to FIG. 11.

Since the organic light emitting diode display according to an exemplaryembodiment of the present invention described with reference to FIG. 8to FIG. 11 may include substantially identical elements to those of theorganic light emitting diode display according to an exemplaryembodiment of the present invention described with reference to FIG. 2to FIG. 6, duplicative descriptions may be omitted.

FIG. 8 to FIG. 11 are process cross-sectional views illustrating amanufacturing method of an organic light emitting diode displayaccording to an exemplary embodiment of the present invention.

Referring to FIG. 8, the buffer layer 120 may be disposed on thesubstrate 110, and the semiconductor 130 may be disposed on the bufferlayer 120.

The first gate insulation layer 141, the first metallic material layer510, and the second metallic material layer 520 may be sequentiallydeposited on the semiconductor 130 and the buffer layer 120.

Referring to FIG. 9, the photoresist pattern 600 may be formed bycoating a photosensitive material on the second metallic material layer520 and then patterning it.

Referring to FIG. 10, the first gate electrode 152 and the first storageelectrode 153 may be formed by etching the second metallic materiallayer 520 using the photoresist pattern 600 as a mask.

The second diffusion barrier layer 159 may be formed by oxidizing thefirst metallic material layer 510 using the photoresist pattern 600 as amask. A part of the first metallic material layer 510, which is disposedunder the first gate electrode 152 and the first storage electrode 153and thus might not be oxidized, may serve as the first diffusion barrierlayer 151.

The first diffusion barrier layer 151 may include titanium (Ti), and thesecond diffusion barrier layer 159 may include titanium oxide (TiO_(x)).

The photoresist pattern 600 may then be removed, and the second gateinsulation layer 142, the second gate electrode 154, the interlayerinsulation layer 160, the source electrode 173, the drain electrode 175,the passivation layer 180, the pixel electrode 191, the pixel definitionlayer 350, the organic emission layer 370, and the common electrode 270may be sequentially formed (see, e.g., FIG. 11).

An organic light emitting diode display according to an exemplaryembodiment of the present invention will be described in more detailbelow with reference to FIG. 12.

Since the organic light emitting diode display according to an exemplaryembodiment of the present invention described with reference to FIG. 12may include substantially identical elements to those of the organiclight emitting diode display according to an exemplary embodiment of thepresent invention described with reference to FIG. 1, duplicativedescriptions may be omitted. A source region and a drain region of asemiconductor may be partially rather than entirely overlapped with asecond diffusion barrier layer. The semiconductor will be describedbelow in more detail.

FIG. 12 is a cross-sectional view illustrating an organic light emittingdiode display according to an exemplary embodiment of the presentinvention.

Referring to FIG. 12, the organic light emitting diode display accordingto an exemplary embodiment of the present invention may include thesubstrate 110, the semiconductor 130 disposed on the substrate 110, thefirst gate insulation layer 141 disposed on the semiconductor 130, thefirst diffusion barrier layer 151 disposed on the first gate insulationlayer 141, the second diffusion barrier layer 159 contacting a lateralsurface of the first diffusion barrier layer 151, and the first gateelectrode 152 disposed on the first diffusion barrier layer 151.

According to an exemplary embodiment of the present invention, thesecond diffusion barrier layer 159 may cover upper surfaces and lateralsurfaces of the source region 132 and the drain region 133 of thesemiconductor 130, and may be substantially entirely overlapped with thesource region 132 and the drain region 133 of the semiconductor 130.According to another exemplary embodiment of the present invention, thesecond diffusion barrier layer 159 may be partially overlapped with thesource region 132 and the drain region 133 of the semiconductor 130.Most of the source region 132 and the drain region 133 of thesemiconductor 130 might not be covered with the second diffusion barrierlayer 159.

The second gate insulation layer 142 may be disposed on the first gateelectrode 152, the second diffusion barrier layer 159, and thesemiconductor 130. The second gate insulation layer 142 may be disposeddirectly on the source region 132 and the drain region 133 of thesemiconductor 130.

A manufacturing method of an organic light emitting diode displayaccording to an exemplary embodiment of the present invention will bedescribed in more detail below with reference to FIG. 13 to FIG. 17.

Since the organic light emitting diode display according to an exemplaryembodiment of the present invention described with reference to FIG. 13to FIG. 17 may include substantially identical elements to those of theorganic light emitting diode display according to an exemplaryembodiment of the present invention described with reference to FIG. 2to FIG. 6, duplicative descriptions may be omitted.

FIG. 13 to FIG. 17 are process cross-sectional views illustrating amanufacturing method of an organic light emitting diode displayaccording to an exemplary embodiment of the present invention.

Referring to FIG. 13, the buffer layer 120 may be disposed on thesubstrate 110, and the semiconductor 130 may be disposed on the bufferlayer 120.

The first gate insulation layer 141, the first metallic material layer510, and the second metallic material layer 520 may be sequentiallydeposited on the semiconductor 130 and the buffer layer 120.

Referring to FIG. 14, the photoresist pattern 600 may be formed bycoating a photosensitive material on the second metallic material layer520 and then patterning it.

Referring to FIG. 15, the first gate electrode 152 and the first storageelectrode 153 may be formed by jointly etching the second metallicmaterial layer 520 and the first metallic material layer 510 using thephotoresist pattern 600 as a mask. The second metallic material layer520 and the first metallic material layer 510 may be jointly etched by awet etching method. A part of the first metallic material layer 510 maybe protruded more than the first gate electrode 152 because of adifference between an etching rate of the first metallic material layer510 and an etching rate of the second metallic material layer 520.

The first gate insulation layer 141 is etched by using the photoresistpattern 600 as a mask. The first gate insulation layer 141 may be etchedby a dry etching method.

Referring to FIG. 16, the second diffusion barrier layer 159 may beformed by oxidizing the first metallic material layer 510 using thephotoresist pattern 600 as a mask. A part of the first metallic materiallayer 510 which is disposed under the first gate electrode 152 and thefirst storage electrode 153 and thus might not be oxidized may serve asthe first diffusion barrier layer 151.

The first diffusion barrier layer 151 may include titanium (Ti), and thesecond diffusion barrier layer 159 may include titanium oxide (TiO_(x)).

The photoresist pattern 600 may be removed, and the second gateinsulation layer 142, the second gate electrode 154, the interlayerinsulation layer 160, the source electrode 173, the drain electrode 175,the passivation layer 180, the pixel electrode 191, the pixel definitionlayer 350, the organic emission layer 370, and the common electrode 270may be sequentially formed (see, e.g., FIG. 17).

While the present invention has been shown and described with referenceto the exemplary embodiments thereof, it will be apparent to those ofordinary skill in the art that various changes in form and detail may bemade thereto without departing from the spirit and scope of the presentinvention.

What is claimed is:
 1. A thin film transistor array panel comprising: asubstrate; an oxide semiconductor disposed on the substrate; a firstgate insulation layer disposed on the oxide semiconductor; a first layerdisposed on the first gate insulation layer; a second layer disposed onthe oxide semiconductor; a first gate electrode disposed on the firstlayer; and a source electrode and a drain electrode connected to theoxide semiconductor, wherein the first layer comprises a metal and thesecond layer comprises a metal oxide including the metal, and whereinthe oxide semiconductor is between the substrate and the first gateinsulation layer.
 2. The thin film transistor array panel of claim 1,wherein a lateral edge of the second layer contacts a lateral edge ofthe first layer.
 3. The thin film transistor array panel of claim 1,wherein lateral edges of the first layer and the first gate electrodelayer are substantially aligned with each other.
 4. The thin filmtransistor array panel of claim 1, wherein lateral edges of the secondlayer and the first gate insulation layer are substantially aligned witheach other.
 5. The thin film transistor array panel of claim 1, whereinthe first gate electrode includes copper, the first layer includestitanium, and the second layer includes titanium oxide.
 6. The thin filmtransistor array panel of claim 1, wherein the oxide semiconductorincludes a channel region, and a source region and a drain regiondisposed on opposite sides of the channel region.
 7. The thin filmtransistor array panel of claim 6, wherein the first gate insulationlayer, the first layer, and the first gate electrode overlap the channelregion of the oxide semiconductor.
 8. The thin film transistor arraypanel of claim 6, wherein the second layer is partially overlapped withthe source region and the drain region of the oxide semiconductor. 9.The thin film transistor array panel of claim 6, further comprising: asecond gate insulation layer disposed on the first gate electrode, thesecond layer, and the oxide semiconductor.
 10. The thin film transistorarray panel of claim 9, wherein the second gate insulation layer isdisposed directly on the source region and the drain region of the oxidesemiconductor.
 11. The thin film transistor array panel of claim 9,wherein the second gate insulation layer is disposed directly on asurface of the second layer.
 12. The thin film transistor array panel ofclaim 9, further comprising: a second gate electrode disposed on thesecond gate insulation layer; and an interlayer insulation layerdisposed on the second gate electrode and the second gate insulationlayer, wherein the source electrode and the drain electrode are disposedon the interlayer insulation layer.
 13. A thin film transistor arraypanel comprising: a substrate; an oxide semiconductor disposed on thesubstrate; a first gate insulation layer disposed on the oxidesemiconductor; a first layer disposed on the first gate insulation layerand including titanium; a second layer disposed on the oxidesemiconductor and including titanium oxide; a first gate electrodedisposed on the first layer; and a source electrode and a drainelectrode connected to the oxide semiconductor, wherein the oxidesemiconductor is between the substrate and the first gate insulationlayer.
 14. The thin film transistor array panel of claim 13, furthercomprising: a second gate insulation layer disposed on the first gateelectrode, the second layer, and the oxide semiconductor.
 15. The thinfilm transistor array panel of claim 13, wherein a lateral edge of thesecond layer contacts a lateral edge of the first layer.
 16. The thinfilm transistor array panel of claim 15, wherein the second layerdisposed on a surface of the first gate insulation layer, and lateraledges of the second layer and the first gate insulation layer aresubstantially aligned with each other.
 17. The thin film transistorarray panel of claim 14, wherein the second gate insulation layer isdisposed directly on a surface of the second layer.
 18. An organic lightemitting diode display comprising: a substrate; an oxide semiconductordisposed on the substrate; a first gate insulation layer disposed on theoxide semiconductor; a first layer disposed on the first gate insulationlayer and including titanium; a second layer disposed on the oxidesemiconductor and including titanium oxide; a first gate electrodedisposed on the first layer; a source electrode and a drain electrodeconnected to the oxide semiconductor; a first electrode connected to thedrain electrode; an organic emission layer disposed on the firstelectrode; and a second electrode disposed on the organic emissionlayer.
 19. The organic light emitting diode display of claim 18, whereina lateral edge of the second layer contacts a lateral edge of the firstlayer.
 20. The organic light emitting diode display of claim 18, whereinthe second layer disposed on a surface of the first gate insulationlayer, and lateral edges of the second layer and the first gateinsulation layer are substantially aligned with each other.